Hydraulic rotary-piston machines



Nov. 6, 1962 Filed July l5, 1959 Nov. 6, 1962 HJ. voN HIPPEL ETAL 3,062,193

HYDRAULIC ROTARY-PISTON MACHINES Filed July l5, 1959 8 Sheets-Sheet 2 Nov. 6, 1962 H. J. voN HIPPEL ETAL 3,062,193

HYDRAULIC RoTARY-PIs'roN MACHINES Filed July 15, 1959 8 Sheets-Sheet 3 '33 Fig. 70

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HYDRAULIC RoTARY-PISTON MACHINES Filed July 15, 1959 8 Sheets-Sheet 4 Nov. 6, 1962v H. J. voN HIPPEL ETAL HYDRAULIC ROTARY PISTON CHIN Nev. 6, 1962 H. J. voN HlPPl-:L ETAL 3,062,193

HYDRAULIC ROTARY-PISTON MACHINES Filed July 15, 1959 8 Sheets-Sheet 6 Fig. 7 E

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HYDRAULIC ROTARY-PIsToN MACHINES Filed July 15, 1959 8 Sheets-Sheet 'T Fig. 6 3 34 ,33 38 32 3l Nov. 6, 1962 H. J. voN HIPPEL. ETAL 3,062,193

HYDRAULIC RoTARYPIsToN MACHINES 8 Sheets-Sheet 8 Filed July 15, 1959 3,062,193 Patented Nov. 6, 1962 iiice 3,062,193 HYDRAULIC ROTARY-PISTON MACHINES Hans Joachim von Hippel, Lunen, Germany, and Alfred Jakob Zwicky, Jona, near Rapperswil, St. Gallen,

Switzerland; said von Hippel assigner to said Zwiciiy Filed July 15, 1959, Ser. No. 827,309 Claims priority, application Germany July 17, 1958 S Ciaims. (Cl. 121-85) This invention relates to an hydraulic rotary piston machine with an annular cavity into which open inlet and outlet pipes for the motive lluid and which is formed of lateral and concentric bounding walls, which are sealed at their transition points, of a stationay part and of a rotatable part, two or more pistons firmly connected with one of said parts projecting into the annular cavity and the annular cavity being divided by movable aps in such a manner that the spaces behind the pistons are connected with the inlet pipe for the motive fluid and the spaces in front of the pistons are connected with the outlet pipe.

The object of the invention is to provide an hydraulic, especially longitudinally extending, rotary-piston machine of the aforesaid kind, which is simple infits construction and reliable in its operation. According to the invention, this is achieved essentially by reason of the fact that, in such a rotary-piston machine, the inlet pipe and the outlet pipe for the motive lluid are arranged uncontrolled, in front of and behind the piston, in the part of the motor that carries the pistons, and the flaps, which divide the annular cavity and are controlled and moved by the pistons by displacement, are arranged on the other part.

A rotary-piston machine constructed in accordance with the invention has, especially, the advantage that, with a simple construction, losses of fluid are reduced to the smallest conceivable amount, a uniform torque is obtained and a very good volumetric efficiency is achieved.

In detail, the invention can be further constructed in such a manner that the outlet pipe is arranged at such a distance in front of the piston concerned that, on rotation through the range of the ap concerned, the portion of the annular cavity behind the flap communicates with the outlet pipe before the piston raises the ap. In this Way, the advantage is chiey obtained that the ap, which is raised by the particular piston concerned, has already been reliably relieved at its back from pressure and therefore does not have to be raised against the full hydraulic pressure.

With special advantage, the invention is carried out in such a manner that the opening of the outlet pipe is arranged at such a distance in front of the corresponding piston that the ap, located in front of the piston, is, on rotating, opened hydraulically bythe fluid located between it and the piston. In this embodiment of the invention, the ap in front of the corresponding piston is therefore already raised by the fluid pressure before the piston touches the ap.

Generally, it is advantage to construct a rotary-piston machine according to the invention in such a manner that the pistons are provided with starting cams for raising and guiding the aps, the said cams being as wide as the flaps. By means of such a construction and arrangement of the surfaces of the piston which come into contact with the flaps, the formation of grooves on the sealing surfaces, which might lead to leakage losses, is effectively prevented.

Embodiments of the invention are also very advantageous, in which the pistons are provided with rollers for lifting and guiding the aps, which are preferably guided on the inside wall of the cylindrical annular cavity.

Conversely, embodiments of the invention are also advantageous, in which the aps are provided on their free ends, with rollers which are mounted in such a manner that, on opening and guiding a ap, the sealing surfaces of the aps do not touch the starting cam of the corresponding piston. A further proposal of the invention is to give the pistons and the flaps a greater width than that of the part of the machine that carries the pistons. In this case, according to the invention, a hammer-shaped construction of the piston is advisable and the corresponding housing is, according to the invention, constructed in such a manner that the side walls of the annular cylindrical cavity, which bound the flaps, are rigidly connected with the Hap carrier. In this connection, the expression flap carrier is to be understood as defining that part of the machine on which the flaps are swingably lxed. In this case, it is advantageous, according to the invention, to arrange on the side walls of the housing additional parts which form a portion of the cylindrical bounding surfaces of the annular cavity. The aps can be supported on these parts, so that friction of the llaps on the rotor part is considerably reduced.

A good and secure sealing and mounting of the flaps against pressures that occur 1s, according to the invention, advantageously obtained by supporting, in a sealing manner, the axles of the flaps in corresponding bulges of the housing over the whole of the Width corresponding to the extent of the pistons. ln this Way, it is possible to t very wide flaps without incurring the danger that they will sag owing to the pressure of oil.

Also, in order to obtain a good sealing and application of the flaps to the side walls of the cylindrical cavity, the aps may, in accordance with a further proposal of the invention, consist, in the extent of their width, of a plurality of parts which are connected together movably or elastically. A flap consisting of metal is, therefore, in the scope of this proposal of the invention, composed of individual strips of metal which are tightly connected together by elastic means such as, for example, strips of rubber that are vulcanised thereon and, owing to their elastic construction, are, on the side, always tightly applied to the side walls of the housing.

By a sealing application of the aps to the running surfaces of the part of the machine that carries the pistons and with a hammer-shaped construction of the pistons on the corresponding cylindrical parts of the portion of the machine that carries the ilaps, the result is obtained, according to the invention, that the flaps are acted upon by a resetting spring which is preferably arranged in the axle of the flaps and which is advantageously so selected that its spring force has a very flat characteristic and therefore ensures a uniform pressing of the flaps.

An effective rendering uniform of the torque of the ma:hine can, according to the invention, also be obtained by making the angular distance between two pistons on one side of the annular cavity greater than on the othen side, so that the aps do not pass the pistons at the same time.

Furthermore, the subject matter of the invention comprises further proposals of advantageous constructions, the object of which is especially to ensure the tightness of the surfaces which act on each other and the maintenance of a reliably sealing air gap between the movable parts.

This object is already served by the composition, according to the invention, of the flaps, in the direction of the width, of a plurality of strips that are connected together elastically. In fundamentally the same maner, according to the invention, other movable parts, such as, for example, the pistons, the piston carriers, i.e. the parts of the machine that carry the pistons, closing members or the like, may be hollow and may be under the pressure of the pressure iluid. It may -be advantageous to divide the cavities into chambers which, if necessary, are kept under different pressures permanently or alternately. If, therefore, the sealing surface concerned is to be kept tight against greater fluid pressure, for example according to the Vdirection of running of the machine, the corresponding cavity is also given a greater fluid pressure by connection to the pressure pipe of the machine. If the pressure, which is to be sealed, is smaller on changing the direction of running, then the pressure in the cavity is reduced by connection to the outlet pipe of the machine, in order also to reduce the friction of the sealing surfaces. In this way, a minimum of leakiness and a minimum of friction between the surfaces that are to be sealed from each other is ensured.

In detail, the invention can be carried out in such a manner that the pistons have the same width as that of the base member that carries the pistons, and the base member consists of two discs which are connected together elastically, by vulcanisation, for example, and which are in one piece with the side walls of the pistons.

It is further possible, in the scope of the invention, to seal the rotor of the machine from the housing by movable sealing surfaces. For example, pressure cylinders with pistons may be arranged in the rotor, advantageously on the periphery, the said pistons pressing movable sealing members against the wall of the housing under the action of the uid pressure.

The invention also is based on the concept of constructing and using rotary-piston machines of the aforesaid kind, Which may preferably be constructed as slow rotors, for cranes, conveyor-belt gears, winch gears and lift drives and, preferably, by constructing the flaps or the pistons as catches which prevent return movement. In this way, there is obtained, especially for all elds of application of such rotary-piston machines, with which loads are raised, principally the advantage that there is already provided, within the motor, a self-locking means which is better than, for example, a gear locking by a worm wheel. In order to prevent damage to the sealing surfaces by the aps on the stopping of the return movement, lthe invention is advantageously carried out by providing the flaps, outside the sealing surfaces, with cams or the like for striking corresponding counter-stops. Consequently, the sealing surface of the ap on the piston does not, according to the invention, support itself in the locking position, but a special cam, which is in a position to receive the whole load.

This proposal of the invention can be used both in the case of rotary-piston machines, which have been constructed for two directions of rotation, and in which the 'aps can, at any time, be put out of operation for one direction of rotation by a controlling gear from the outside, and With special advantage for machines with flaps provided for only one direction of rotation.

If the rotary-piston machine according to the invention is constructed for rotation in only one direction, the flaps for the opposite direction of rotation are dispensed with and the arrangement of a plurality of flaps for only one direction of rotation improves the sealing and thevolumetric, eiciency. In a specially preferred embodiment of the invention, the rotor of the rotarypiston machine may be connected with the drum of, for example, a winch directly or through transmission gear and, in this case, the housing of the rotary-piston machine may be constructed, on its periphery, as a drum for a band brake or a cheek brake in such a manner that, by lifting the brake the brake drum can be rotated backwards rapidly or slowly as desired for lowering the load. In the case of such an embodiment of the invention, the rotor can, for example for raising the load, thus be rotated in relation to the housing by 'means of oil pressure, Whilst the housing is held stationary by the band brake, whereas, on lowering the load, the housing can be rotated backwards by lifting the band brake and the brake is lifted for releasing the rotation of the housing by mechanical action or by hydraulic operation and renders possible a very slow lowering of the load. The housing is advantageously provided with cooling fins, so that the energy, that has beenconverted into heat, can be easily dissipated. This arrangement has the advantage that, also on lowering the load, the housing is heated to approximately the same extent as the flaps, so that, notwithstanding the small amount of clearance between a flap and the housing, a jamming of the flaps owing to excessive thermal expansion, cannot occur.

Owing to the invention, also in the case of cranes inter alia, only a single motor is necessary for all the movements of the crane and, on the employment of the invention on ships, only a single pump in the engine room is necessary for all the winch mechanisms.

Other advantageous details of the invention can be seen in the accompanying drawings in which the invention is illustrated by way of example.

In the drawings:

FIGURE l is a longitudinal section of a rotary-piston machine according to the invention taken along line I-I in FIG. 2;

FIGURE 2 shows the machine of FIGURE l in partial cross-section taken along II-II in FIG. l;

FIGURE 3 is a cross-section of a portion of another embodiment;

FIGURE 4 is a cross-section of a special construction of a flap;

FIGURE 5 shows another embodiment of the invention in diagrammatic representation and in cross-section;

FIGURES 6 and 7 show a special construction of the machine according to the invention for rope Winches and the like in cross-section and in longitudinal section respectively, the section of FIG. 6 being taken along line VI-VI in FIG. 7;

FIGURE 8 shows a special embodiment of a piston and piston-carrier in cross-section;

FIGURE 9 is a plan corresponding to FIGURE 8;

FIGURE l0 is a section through FIGURE 8 taken vertically to the plane of the paper; and

FIGURE 1l is a section showing the outlet openings arranged in different position than in FIG. 6.

In the case of the embodiment of the invention represented in FIGURE 1, 1 denotes the hollow shaft of the machine on which is fixed the rotor 2 which rotates in the housing that is generally Vdenoted by 3, and comi prises cylindrical wall 3a and side walls 14. These walls define an annular cavity between them. The rotor y 2 carries the pistons 4, advantageously at least two pistons. 'Ihe pistons 4 are provided, on both sides, with starting cams or projections 5.

Two groups of flaps are arranged in the housing 3 comprising flaps 6 which are effective during counterclockwise operation of the rotor and aps 7 eiective during clockwise operation of the rotor. Both types of the flaps 6 and 7 are pivotally movable in the housing 3 about pivot axes 8 which have an extension 8 (FIG. 5) projecting outwardly. An arm 9 is secured to extension 8 to which one end of a spring 45 is fastened at 9 the other end of which spring is connected by means of a pin 42 to the arm 46 of a double armed lever which pivots about a pivot support 47. The arrangement of the pivot support 47 on housing 3 makes it possible to optionally operate one group of aps while the other group is idle. The arms 48 project beyond the pivot points 47 and have an abutment member 49 which engages a radial slot 50 in a rotatable ring 51 which is coaxial with the shaft 1. Rotating the ring 51 to a predetermined extent causes lever 46, 48 to move the supporting pins 42 for springs 45 to assume such positions with respect to the pivot axes 8 of the flaps 6, 7 as to cause either aps 6 or 7 to be pulled into the annular cavity 10 or to engage the respectiverecesses 6 or 7' in the wall ofA the housing. The mounting of levers 46, 48 in alternately opposite positions results in one group of aps being rendered operative while the other group is in position of rest. A knob or handle 52 is provided for rotating ring 51.

As illustrated in FIG. 5, ring 51 is in its end position b. All lever ends 42 for the aps 7 are along an outer circle so that springs 45 keep all aps 7 in their position of rest. Simultaneously all pins 42' on levers 46, 4S for the flaps 6 are disposed along an inner circle so that the ilaps 6 are moved into active position by means of springs 45. When pressure fluid is supplied by Way of channels 12a, 12 the motor rotates counterclockwise.

If the motor is to rotate clockwise in the housing 3, the direction of flow of the pressure fluid is reversed, while at the same time, the corresponding shifting of tl e groups of aps is undertaken. The pressure fluid is now supplied through annular channel 11a disposed around shaft 1 and by way of bore 11 into annular cavity 10, while the return ow is through bore 12 and annular channel 12a. Gaskets 53 provide liquid seals between the end cap 3b and a divider 55 between bore 12a and channel 11a and gaskets 54 provide seals between cap 3b and rotor 2. As a result of the pressure fluid entering7 through channels 11a, 11 or 12a, 12, a

high pressure exists always behind the pistons 4 with respect to the direction of rotation and a low pressure exists ahead of the pistons, because that part of the annular cavity 1G which is ahead of the pistons is connected with the discharge channel. Thus, as a result of this difference in pressure the pistons 4 with rotor 2 move in counter-clockwise direction in the housing 3 under the operating conditions illustrated in FIG. 2 if the flaps 6 to the right of the piston 4, i.e. behind the piston in direction of rotation close the space with respect to the space ahead of the following piston which space is not under pressure, being in communication with the discharge channels, which in that case are channels 12 and 12a.

To prevent the ow of the pressure fluid between the flaps 6 and 7 and the housing 3, axially extending gaskets 43 are pro-vided in the recesses 16 proximate the axes of the flaps. The cavity in front of and behind the pistons 4 is thus divided by the flaps 6 in such a manner that the parts of the annular cavity 1t) communicate behind the pistons 4, with the inlet pipe 11 of the motive fluid and the parts of the annular cavity in front of the pistons 4 communicate with the outlet pipe 12 for the motive fluid. The inlet pipes 11 and the outlet pipes 12, which are associated, in the same manner, with the second (or third or fourth) piston of the machine, are all, according to the invention, uncontrolled and are arranged, in front of and behind the pistons 4, in the rotor 2 which carries the pistons 4, and the flaps 6 or 7, which divide the annular hollow cavity, are swingably arranged on the other part, namely on the housing 3.

When the rotor 2 rotates in the housing 3 under the action of the difference in pressure in front of and behind the pistons 4 and thus arrives in the range of a ap 6 which stood, on the other side, under the action of the pressure which prevails behind the next piston 4, the outlet pipe 12 is arranged in such a manner that the cavity behind the ap 6 already communicates with the outlet pipe 12 before the piston 4 touches the flap 6 with its starting surface 5, so that the raising of the ap 6 takes place without any pressure resistance.

On the other hand, as shown in FIG. l1, embodiments of the invention are also possible, in which the outlet openings of the conduits 11 are arranged at such a distance in front of the corresponding pistons 4 that the ap 6, that is then in front of a piston 4, is already raised hydraulically by the hydraulic pressure produced between the flap 6 and the piston 4 by the damming of the liquid. Contacting with the starting cam 5 is then effected only during the nal raising of the flap 6 to the inside of the wall of the annular cavity 10, whilst the lifting of the flap 6 from its sealing surface is effectedA smoothly by the aforesaid increase of pressure of the fluid in the part of the annular cavity in front of the piston 4.

The starting cams 5 of the pistons 4 are advantageously made as wide as the flaps 6.

As shown in FIGURES 3 and 11, the pistons 4 may in lieu of the starting cams 5, be provided with rollers 13 which are guided on the inside of the Wall of the cylindrical annular cavity 10. On the other hand, it is also possible conversely to provide the front edge of the flaps 6 or 7 with such rollers 13 which are then mounted in such a manner that, on opening and guiding the ap, its sealing surfaces do not touch the starting cam of the corresponding piston, but contact is effected exclusively by the rollers 13.

The section shown in FIGURE 1 also shows an important feature of the present invention, in which the pistons 4 and also the corresponding flaps 6 and 7 have a greater width than the rotor 2 which carries the pistons 4. On the whole, there is thus produced a hammer-shaped construction of the part of the machine that is formed by the rotor 2 and the pistons 4. Also, in this embodiment, the side walls 14 of the annular cylindrical cavity 16 are rigidly connected with the housing 3 which carries the aps 6 and 7. Moreover, there are arranged, on the side walls 14 inwardly projecting shoulders 15 which form a part of the cylindrical bounding surfaces of the annular cavity 10.

As shown in FIGURE 2 the flaps 6 and 7 are supported, at their backs, in grooves 16 of the housing 3 over the whole extent of their width which corresponds to the width of the pistons 4. Seals 43 are provided in the grooves 16 to seal the backs of the aps.

In the embodiment shown in FIGURE 1, the rotor 2 is sealed from the housing part 14 and, especially,l from the part 15 of the housing by the movable walls 17 which are acted upon by pistons 19 which, in turn, are put under pressure by the pressure pipe 11. In this Way, the movable walls 17 are constantly pressed by pressure against the corresponding opposite faces of the housing part 14 or against the housing part 15. Arranged between the sealing faces proper of the housing and the rotor are, advantageously, strips 20 of a special material, preferably carbon strips or rings. A deformable or resilient annular gasket 20a or 20b may also be provided in the rotor whereby pressure fluid is continuously supplied to the friction surface by way of channel 12.

In the embodiment illustrated in FIG. 4 a spring 21 is arranged in the axle or shaft 21 of flaps 6 and 7 which maybe a rotary bar spring or a spiral spring of fiat characteristic and which tends to press the corresponding ap into the annular cavity 10 so that the sealing surfaces are pressed into engagement with the sealing surfaces on the rotor 2 or on the portion 15 of the housing 3. This arrangement of spring 21 in the axles or shafts of the flaps can be used together with the controlling means in accordance with FIG. 5.

FIGURES 6 and 7 represent embodiments of the invention which are of advantage especially when. a slowly rotating motor is employed, according to the invention, for Winches, lifts, cranes or conveyor belts.

In the embodiment shown in FIGURE 6 which is a section taken along line VI-VI in FIG. 7, the same parts are denoted by the same reference numerals as in the description of FIGURES 1 and 2. In FIGURES 6 and 7, 22 denotes the stationary pivot of a mechanically or hydraulically operated brake lever 23, which can be brought into action on a brake belt 24 of the housing 3 or of a brake drum connected with the housing 3. The ends of the brake belt 24 are fastened to lever 23 at the pins 23a.

The rotor 2, together with the pistons 4, are arranged within the housing 3, the uncontrolled conduits for the 7 pressure uid being denoted in front of and behind the pistons 4 by 11 and 12.

In the housing 3, there are swingably arranged, in the illustrated embodiment, the ap 6 for the left-hand rotation and the flap 7 for the right-hand rotation, which flaps divide the annular cavity 10 in front of and behind the pistons 4 in such a manner that the spaces behind the pistons 4 communicate with the inlet pipe 11 of the motive uid and the spaces in front of the pistons communicate with the outlet pipe 12. Also, arranged on the pistons 4 are rollers 13 for each direction of rotation, by means of which the flaps 6 and 7 are raised on the passage of the pistons 4, the rollers 13 coming into contact, outside the sealing surface opposite the rotor, with the aps 6 and 7. However, it is also possible to arrange and construct the feed and discharge conduits in such a manner that flaps 6 and 7 are lifted by the pressure that is dammed in front of the pistons 4 and are then nally raised by the rollers 13.

As can be seen from the drawing, the ilaps 6 and 7 are, outside the sealing surfaces with which they are applied against the rotor, provided with cams or grooves 45a which can be applied against corresponding cams 25 and 26 on the rotor 2 or the pistons 4, so that the flaps 6 and 7 are used as locks against automatic return. The cams 25 and 26 or the corresponding grooves in the aps 6 and 7 are formed in such a manner by the inclination of the oblique surfaces 41 that the ilaps 6 and 7 are raised from the sealing surfaces on the rotor 2 before they move into the locking position. In the portion of annular cavity between two pistons 4, a double pair of flaps 6 and 7 is arranged, so that at least one flap is always located in the sealing position between the pistons, even when the other ap is in the locking position, i.e. resting on a cam and is there somewhat raised. It is a particular advantage Vof the grooves 45a that the force responding to the reverse action which must be transferred to the housing 3 acts transversely of the axes of the flaps 8 and the sealing edge at the end of the ap is not subjected to pressure.

In the embodiment illustrated in FIGURE 7, the housing 3 is in the form of a brake drum and is rotatably mounted over ball bearings 27 in the stand 28. 29 denotes, for example, arope winch or the drum of a conveyor belt with which the rotor 2 is connected directly or through a transmission gear. 30 denotes cooling iins.

In the embodiment represented in FIGURES 6 and 7, va load, for example, can thus be raised by winding a rope on the rope drum 29 by rotating the rotor 2. When the rotor 2 is stopped, the load is held by the flaps 6 or 7 which act as pawls. The lowering of the load is, in the case of locking aps, effected by lifting the brake belt 24 which releases for rotation the housing 3 that carries the flaps.

Generally, the invention can be carried out by arranging, between the hydraulic motor and the rope drum, a brake coupling the laminae of which are loosened by hydraulic pressure.

In FIGURES 8 to 10, 2 again denotes the rotor which, together with the piston 4, consists of one piece and which, in turn, rotate in the annular cavity 10 that is formed by the rotor 2 and the housing 3. In the embodiment represented in FIGURES 8 and 9, the pistons 4 and the adjoining part of the rotor 2 are hollow and the cavity 31 can be divided into a plurality of chambers by partitions 32.

The cavity 31 is covered on its outside by an inserted closing member 33 which, at its edges, is inserted into groooves 34 in the piston 4. The side walls of the piston 4 and of the rotor 2 can be made elastic by thinning them in the parts 37, as shown. The cavity 31 is closed against the outside by a cup-shaped body 38 which consists of rubber or other elastic material in which the uid pres sure, which enters through the bores 11a or 12a, can be eiective. It is also possible to make the side walls 35 of 8 the piston 4 and of the rotor 2 elastic by means of slits 36. In this case, it is necessary to replace the cup-shaped body 38 by a bladder 38a which consists of elastic material and the inside of which communicates with the fluid pressure entering through the bore 39.

By means of the Huid pressure present inside the cavity 31 or the two chambers formed by the partition 32, the closing mem-ber 33 is pressed against the cylindrical part of the housing 3 and, under the action of this fluid pressure, the side walls are applied sealingly against the end walls of the housing 3. At the same time, the circular ring 4G is, in this way, beneath the pistons 4 proper of the rotor 2, pressed against the side walls of the housing 3 and sealed.

The chambers formed by the partition 32 can also be kept under different pressures in order to press their walls at times with only such a pressure against the corresponding walls of the housing 3 as is just necessary for sealing off the pressure prevailing in the annular cavity 10. Generally, the rotor 2, in the embodiment represented, consists of two circular discs, which are connected together on the outer periphery by intermediately vulcanised rubber 33 and the inner cavity of which is lled with pressure oil and which, when the two discs are joined together, also form the piston 4.

The invention has hereinbefore been explained solely with the aid of examples in which the part of the machine that carries the pistons rotates and the part that carries the flaps is stationary. Although this is the preferred embodiment of the invention, it is, if necessary, also possible to employ the proposal of the invention on machines in which, conversely, the part which carries the pistons is stationary and the part which carries the flaps rotates.

We claim:

1. A hydraulic rotary piston machine operable by means of a pressure iluid in two directions of rotation, said machine comprising, in combination, a source of uid under pressure, a cylindrical housing having an outer Wall, radially inwardly extending side wall portions and annular shoulders extending from said side Wall portions toward one another to define an annular cavity concentric with the axis of said housing, two sets of aps, each comprising at least four flaps for each direction of rotation, one said set being operative while the other said set is inoperative, said aps being pivotally supported within said housing wall adjacent said annular cavity and having each a retracted inoperative position against said housing wall and an operative position transversely of said cavity, each said set of aps in operative position dividing said cavity into compartments, spring means connected to and biasing said flaps into operative position, a rotor arranged concentric with the axis of said housing having a plurality of pistons extending laterally of said rotor,

radially into and transversely of said annular cavity and being of greater width than said rotor, at least one inlet and one outlet pipe for said iluid extending through said rotor to said cavity, said flaps being arranged in a manner that the compartments following said pistons in the direction of rotation of said rotor are connected with an inlet pipe and the compartments preceding the pistons are connected with an outlet pipe, and the free edges of said aps engaging the said inwardly extending annular shoulders laterally of the rotor before the difference in fluid pressure within the cavity urges said ilaps tightly against said shoulders, said outlet pipe being located a predetermined distance ahead of one of said pistons in a manner that said aps are initially urged towards their withdrawn position by the difference of uid pressure on opposite flap sides.

2. A hydraulic rotary piston machine operable by means of a pressure uid in two directions of rotation, said machine comprising, in combination, a source of iluid under pressure, a cylindrical housing having an outer wall, radially inwardly extending side wall portions and annular shoulders extending from said side wall portions toward one another to define an annular cavity concentric with the axis of said housing, two sets of flaps, each comprising at least four flaps for each direction of rotation, one said set being operative while the other said set is inoperative, said iiaps being pivotally supported within said housing wall adjacent said annular cavity and having each a retracted inoperative position against said housing wall and an operative position transversely of said cavity, each said set of flaps in operative position dividing said cavity into compartments, spring means connected to and biasing said iiaps into operative position, a rotor arranged concentric with the axis of said housing and having a plurality of pistons extending laterally of said rotor, radially into and transversely of said annular cavity and being of greater width than said rotor, at least one inlet and one outlet pipe for said fluid extending through said rotor to said cavity, said flaps being arranged in a manner that the compartments following said pistons in the direction of rotation of said rotor are connected with an inlet pipe and the compartments preceding the pistons are connected with an outlet pipe, and the free edges of said iiaps engaging the said inwardly extending annular shoulders laterally of the rotor before the ditlerence in iluid pressure within the cavity urges said aps tightly against said shoulders, said outlet pipe being located a predetermined distance ahead of one of said pistons in a manner that said aps are initially urged towards their withdrawn position by the difference of fluid pressure on opposite flap sides, and a plurality of rollers, at least one mounted on each said piston, arranged to contact said flaps while in any position other than retracted position to raise said iiaps toward retracted position as said pistons move relative to said flaps.

3. A hydraulic rotary piston machine operable by means of a pressure iluid in two directions of rotation, said machine comprising, in combination, a source of uid under pressure, a cylindrical housing having an outer wall, radially inwardly extending side wall portions and annular shoulders extending from said side Wall portions toward one another to define an annular cavity concentric with the axis of said housing, two sets of flaps, each comprising at least four aps for each direction of rotation, one said set being operative while the other said set is inoperative, said flaps being pivotally supported within said housing wall adjacent said annular cavity and having each a retracted inoperative position against said housing wall and an operative position transversely of said cavity, each said set of aps in operative position dividing said cavity into compartments, spring means connected to and biasing said flaps into operative position, a rotor arranged concentric with the axis of said housing and having a plurality of pistons extending laterally of said rotor, radially into and transversely of said annular cavity and being of greater width than said rotor, at least one inlet and one outlet pipe for said tiuid extending through said rotor to said cavity, said flaps being arranged in a manner that the compartments following said pistons in the direction of rotation of said rotor are connected with an inlet pipe and the compartments preceding the pistons are connected with an outlet pipe, and the free edges of said iiaps engaging the said inwardly extending annular shoulders laterally of the rotor before the difference in fluid pressure within the cavity urges said iiaps tightly against said shoulders, said outlet pipe being located a predetermined distance ahead of one of said pistons in a manner that said aps are initially urged towards their withdrawn position by the diiference of fluid pressure on opposite ilap sides, a plurality of rollers, at least one mounted on each said piston, arranged to contact said flaps while in any position other than retracted position to raise said flaps toward retracted position as said pistons move relatively to said aps, said rollers rolling along and being guided by at least a portion of a wall of said annular cavity.

4. A hydraulic rotary piston machine operable by means of a pressure Huid in two directions of rotation, said machine comprising, in combination, a source of uid under pressure, a cylindrical housing having an outer wall, radially inwardly extending side wall portions and annu'- lar shoulders extending from said side wall portions t0- ward one another to define an annular cavity concentric with the axis of said housing, two sets of flaps, each compring at least four flaps for each direction of rotation, one said set being operative while the other said set is inoperative, Vsaid ilaps being pivotally supported within said housing wall yadjacent said annular cavity and having each a retracted inoperative position against said housing wall and an operative position transversely of said cavity, each said set of flaps in operative position dividing said cavity into compartments, spring means disposed inside the pivot shafts of said flaps and connected to and biasing said ilaps into operative position, a rotor arranged concentric with the axis 0f said housing and having a plurality of pistons extending laterally of said rotor, radially into and transversely of said annular cavity and being of greater width than said rotor, at least one inlet and one outlet pipe for said Huid extending through said rotor to said cavity, said flaps being arranged in a manner that the compartments following said pistons in the direction of rotation of said rotor are connected with an inlet pipe and the compartments preceding the pistons are connected with an outlet pipe, and the free edges of said Flaps engaging the said inwardly extending annular shoulders laterally of the rotor before the difference in fluid pressure within the cavity urges said ilaps tightly against said shoulders, said outlet pipe being located a predetermined distance ahead of one of said pistons in a manner that said aps are initially urged towards their withdrawn piston by the difference of fluid pressure on opposite ap sides, a plurality of rollers, at least one mounted on each said piston, arranged to contact said flaps while in any position other than retracted position to raise said flaps toward retracted position as said pistons move relatively to said iiaps, said rollers rolling along and being guided by at least a portion of a wall of said annular cavity.

5. A hydraulic rotary piston machine operable by means of a pressure fluid in two directions of rotation, said machine comprising, in combination, a source of fluid under pressure, a cylindrical housing having an outer wall, radially inwardly extending side wall portions and annular shoulders extending from said side wall portions toward one another to define an annular cavity concentric with the axis of said housing, two sets of aps, each comprising at least four flaps for each direction of rotation, one said set being operative while the other said set is inoperative, said aps being pivotally supported within said housing wall adjacent said annular cavity and having each a retracted inoperative position against said housing wall and an operative position transversely 0f said cavity, each said set of aps in operative position dividing said cavity into compartments, spring means connected to and biasing said aps into operative position, a rotor arranged concentric with the axis of said housing and having a plurality of pistons extending laterally of said rotor, radially into and transversely of said annular cavity and being of greater Width than said rotor, at least one inlet and one outlet pipe for said fluid extending through said rotor to said cavity, said aps being arranged in a manner that the compartments following said pistons in the direction of rotation of said rotor are connected with an inlet pipe and the compartments preceding the pistons are connected with an outet pipe, and the free edges of said flaps engaging the said inwardly extending annular shoulders laterally of the rotor before the difference in fluid pressure within the cavity urges said flaps tightly against said shoulders, said outlet pipe being located a predetermined distance ahead of one of said pistons in a manner that said aps are initially urged towards their withdrawn position by the'ditference of uid pressure on oppositefap sides,

said pistons having 'cavities communicating by way of 6. A hydraulic rotary piston machine operable by means of a pressure uid in two directions of rotation, sa1d machine comprising, in combination, a source of fluid y under pressure, a cylindrical housing-having an outer wall, radially inwardly extending side wall portions and annular shoulders extending from said side wall portions toward one another to dene an annular cavity concentric with the axisv of said housing, two sets of aps, eachcomprising at'least four flaps for each direction of rotation, one said set being operative while the other said set is inoperative, said llapsbeing pivotally supported within said housing wall adjacent said annular cavity and having each a retracted in operative position against said housing wall andan operative position transversely of said cavity, eachsaid set of aps in operative position dividing said cavity into compartments, springv means Aconnected to and biasing lsaid flaps into operative position, a rotor arranged concentric with the axis ofV said housingai'id havingka plurality of pistons 1 extending `laterally of -said rotor,

Y radially intoV and transversely of said annularcavityand being of greater widthV thanV said rotor, at least one inlet and one outlet pipe for said uid extending through said rotor to said cavity, said flaps being arranged in'a manner that the compartments following said` pistons in the direction of rotation of said rotor are connected with an inlet pipe and the compartments preceding the' pistons are connected with an outlet pipe, and the Vfree edges of said aps engaging the said inwardly extending annular shoulders laterally of the rotor before the dterence in fluid pressure within the cavity urges said flaps tightly against said shoulders, said'outlet pipe being' located a prede-l Vtermine'd distancek ahead of one of said pistons in a manner that said flaps are initially urged towards their withdrawn position by the difference of iiuid pressure on opposite liap sides, said pistons having cavitiesin com municationlwth said source of iiuid undenpressurefby way of apertures in said rotor and having yielding walls 'extensible against the adjacent cylindricaland'lat'eral walls of said housing thereby formingy a fluid tight seal with said walls, and each saidpiston comprising a cup-like member movable radially outwardly against said cylindrical-outer wall.

7. A hydraulic rotary piston machine operable 'by means'of a pressure iiuid in two directions'of rotation, said machine comprising, in combination, a source of uid under pressure, a ycylindrical housing having an outer wall, radially inwardly extending side wall portions and annular shoulders extending fromsaid side wall portions toward one another to deiine an annular cavity concentric with the axis of said housing, two sets of iiaps, each comprisingv at least four aps for each direction of rotation, one said lset being operative while the other said set isvinoperative, said flaps being pivotally supported' v within said housing wall adjacent said annular' cavity vand having each a retracted inoperative position against 'said Y housing wall and an operative position transversely of said cavity, each said set of iaps in operative position dividing said cavity into compartments, spring means connected to and biasing said aps into operative position, a rotor arranged concentric with the axis of said housing and having a plurality of pistons extending laterally of said rotor, radially into and transversely of said annular cavity and being of greater width than said rotor, at least one inlet and one outlet pipe for said iiuid extending through said rotor to said cavity, said flaps being arranged in a manner that the compartments following said pistons in the' direction 'of rotation of said rotor are connected with an inletpipe and thecompartmentspreceding the pistons are connected with an outlet pipe, and the free edges of said flaps engaging the said inwardly'extending annular shoulders laterally of the rotor before thel diff ference in uid pressure within the cavity urges said flaps tightly against said shoulders, saidaps having grooves adjacent the free ends thereof and said pistons having projections adapted to be engaged by said grooves to effect a self-lockingaction opposing any reversing tendency of the machine.

8. A hydraulic rotary piston machine operable by means vof a pressure fluid in two directions of rotation, said machine comprising, in combination,` a source ofciiuid under pressure, a cylindrical housingy having an outer wall, radially inwardly extending side wall portions and annular shoulders extending from said sidewall portions toward one another to define an annular cavity concentric with the axis of said housing, two sets of liaps, leach comprising at least four iiaps for each direction of rotation,`

one said set being operative while the other vsaid set is inoperative, said iiaps being pivotally supported within.

said housing Wall adjacent said annular cavity and having each a retracted inoperative position against said housing biasing said aps into operative position, a rotorxarrariged concentric with the axis of said housing and., plurality of pistonsextending laterally of said rotor, Atrad.-

" ally into and transversely of said annular cavity and' being ot greater width than said rotor, at least one inlet and one outlet pipe for said fluid extending through said rotor to said cavity, said flaps being arranged in a manner j that the compartments following said pistons inthe direction of rotation of said rotor are connected with an inlet pipe and the compartments preceding the pistons are connected with` an outlet pipe, and the free edges of said aps engaging the'said inwardly'extending annular shoulders laterally of the rotor beforeV the difference in uid pressure within the cavity urges said aps -tightly against said shoulders, said` flaps having grooves adjacentthe free ends thereof `and said pistons having projections adapted to be engaged by said grooves toV etect aselflocldng `action opposing any reversing tendency of the machine, said grooves and projections having such con,- formation as to transmit the locking stress perpendicularly to the pivot axes of said aps while avoiding Contact Vbef tween the free edges of said flaps andsaid projections.

References Cited inheilef this patent l n UNITEDLST'IES PATENTS 426,976 Wright Apr. 29,1890 453,615 Brosuis June 9, 1891 604,960 Boris May .31, l1898 696,245 Kennedy Mar. 25, 1902 741,476 Flatau Oct. 13, 1903 823,607 MacDonald Juiy-19, 1906 g 1,345,526 Adams july 6, 1920 1,611,172 t Edson Dec. 21, 1926 2,289,387 Stephens July 14, 1942 2,445,585 Shaft July 20, 1948v 2,550,849 Morris May -1, 1951 2,823,775 Zwayer Feb. 18, 1958 2,831,554 Reynolds Apr. 22, 1958 FOREIGN PATENTS 4,708 Great Britain 1822 139,509 Germany Mar. 20, 1903 France Oct. 4, 192,2 

